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Biomedical subjects

A J Matas

Publications and source records attributed to A J Matas.

At least 343 records · Page 19Linked to original sources
PubMed1979

Bone marrow transplantation for correction of enzyme deficiency disease.

Mutant acatalasemic mice provide a prototype of congenital enzyme deficiency disease. Normal blood catalase levels were achieved permanently in congenitally acatalasemic mice by transplantation of bone marrow cells from congeneic normal catalasemic mice using relatively small numbers of cells following whole body irradiation. The increase in blood catalase activity was physiologically effective as demonstrated by the protection of the previously acatalasemic mice against the otherwise lethal effects of hydrogen peroxide injections. Bone marrow transplantation has the potential to provide a continuous source of some enzymes and may be applicable as treatment for certain congenital enzyme deficiency diseases.

Acatalasia↗
PubMed1978

Autotransplantation of pancreatic fragments to the portal vein and spleen of totally pancreatectomized dogs: a comparative evaluation.

Forty-nine dogs were made diabetic by total pancreatectomy. Fifteen untreated pancreatectomized animals survived a mean (+/-S.E.) of 7.0 +/- 1.1 days with a mean (+/-S.E.) plasma glucose level of 402 +/- 26 mg/100 ml before death. The pancreata of 32 dogs were distended with cold (4 degrees ) Hanks' solution, minced, digested with collagenase (600 U/ml tissue) for 15-25 minutes, and autotransplanted either into the splenic artery (three dogs), directly into the splenic pulp (21 dogs), or into the portal vein (ten dogs). Tissue infusion into the splenic artery resulted in infarction and persistent hyperglycemia. Direct implantation into the splenic pulp of tissue digested for 15, 20 and 25 minutes resulted in permanent normoglycemia (fasting plasma glucose < 150 mg/100 ml) in 7 of 8, 7 of 7, and 6 of 6 dogs respectively. Glucose tolerance test mean (+/-S.E.) K values (% decline of plasma glucose concentration/minute) in these groups two weeks after transplantation were 1.20 +/- 0.20%, 1.60 +/- 0.25 and 0.70 0.08% respectively, indicating that 20 minutes digestion was best for intrasplenic transplantation. Tissue prepared in the optimal manner (20 minutes digestion) and embolized into the liver resulted in normoglycemia in three of eight dogs, and a mean (+/-S.E.) K value of 0.77 +/- 0.10%. Both dogs receiving tissue dispersed for 25 minutes into the portal vein remained hyperglycemic. In the dogs subjected to intraportal transplantation, portal pressure rose from a mean (+/-S.E.) of 6.5 +/- 0.6 cm H(2)O before to 21.9 +/- 2.2 cm H(2)O immediately after tissue embolization, but declined to 6.5 +/- 1.0 cm H(2)O by ten weeks in animals becoming normoglycemic. We conclude that in dogs direct implantation of pancreatic tissue into the splenic pulp is superior to embolization into the portal vein or splenic artery because the splenic circulation is not compromized, portal hypertension is obviated, and glucose metabolism is best controlled as judged by glucose tolerance test K values.

Amylases↗
PubMed1978

[Autotransplantation of pancreas fragments in dogs with total pancreatectomy without separation of exo and endocrine tissue].

By total pancreatectomy 41 dogs were made diabetic. Of these, 15 dogs remained untreated, served as diabetic controls, and died within x = 7 +/- 1 days postoperatively. In the experimental groups the best results were obtained (as judged by K values of iv glucose tolerance test and iv Tolbutamide test curves) after 20 min of incubation with collagenase and immediate transplantation into the splenic pulp. After 15 min and 25 min of incubation, normoglycemia regularly occurred, but in the 20 min collagenase group the K values resembled most closely those of normal dogs. The animals stayed normoglycemic and were observed for up to 6 months. Splenectomy led to reocurrence of the diabetic state and death within 4.8 +/- 1.5 (S.E.) days.

Animals↗
PubMed1978

The immunohistopathology of glomerular antigens. II. The glomerular basement membrane, actomyosin, and fibroblast surface antigens in normal, diseased, and transplanted human kidneys.

Immunofluorescent studies have demonstrated that actomyosin (AMY) is present in the mesangium in a restrictive pattern, whereas fibroblast surface antigen (FSA) has a more extensive mesangial distribution. Antibody to glomerular basement membrane (GBM) is localized to the GBM. One hundred ninety-six tissue samples, including 17 from normal subjects, 94 from patients with primary renal diseases, and 85 from transplanted kidneys, were examined for changes in distribution of AMY, FSA, and GBM antigens. The distribution of AMY and FSA in the mesangium is markedly increased in width in patients with diabetic nephropathy, and the GBM is thickened. AMY and FSA are mildly increased in patients with glomerulonephritis and GBM is normal. Patients with membranoproliferative glomerulonephritis (MPGN) show a loss of all glomerular antigens. Increased mesangial AMY was found in 12 of 37 transplanted kidneys in diabetic patients vs 4 of 33 nondiabetics 0 to 4 years after transplantation (P < 0.025). This difference is more notable at 2 to 4 years, with 5 of 9 diabetics showing increased AMY vs 0 of 6 nondiabetic patients (P < 0.0005). In MPGN, 5 of 8 tissues showed decreased mesangial AMY vs 3 of 36 diabetic patients (P < 0.0005) and 1 of 32 patients with other glomerulopathies (P < 0.0005). GBM thickening is not associated with specific pretransplant diseases. In transplanted kidneys, the pattern of FSA is dissociated from that of AMY: over half of all patients have increased FSA, even when AMY is normal. Whether this unique finding in transplanted kidneys reflects an increase in the synthesis of FSA by mesangial cells or the failure to clear this (circulating) antigen from the mesangial matrix is unknown.

Actomyosin↗
PubMed1978

Clinical and experimental transplantation in enzymatic deficiency disease.

Allotransplantation provides another strategy for the treatment of metabolic diseases. In disorders which primarily affect a specific tissue or organ, appropriate allografts have already proved therapeutically effective. Most of these diseases presumably result from dominantly inherited structural genetic defects. Metabolic transplantation, the grafting of tissues for the continuous production of the normal gene products, can provide effective treatment in appropriate, inherited, metabolic diseases. However, it must be emphasized that this approach is exploratory, and further studies in experimental model systems must be continued. Future advances in immunology and transplantation biology may increase the potential effectiveness of allotransplantation for the treatment of metabolic diseases.

Animals↗
PubMed1978

The fate of intraportally transplanted islets in diabetic rats. A morphologic and immunohistochemical study.

Streptozotocin-induced diabetes in the rat can be reversed by the transplantation of isogenic islets of Langerhans from neonatal donors. We studied the morphology of intraportally transplanted islets with the aid of the immunoperoxidase staining technique to identify insulin-, glucagon-, somatostatin-, and pancreatic polypeptide-containing cells at 24 hours, 48 hours, 1 week, 2 weeks, 4 weeks, 39 weeks, and 65 weeks after transplant. Embolized pancreatic tissue, composed of approximately 80% acini and 20% islets, is initially distributed throughout the liver mainly to terminal branches of the portal system. Endothelialization and organization occur rapidly with the smaller fragments and within the first 4 weeks for larger thrombi. Exocrine pancreatic elements largely disappear as islet cells move into the hepatic lobules from the portal spaces. At 65 weeks after transplant, all islet cell types can be identified within large complex islet structures. The results of this study establish the survival and continued function of all known rat pancreatic islet cell types long after transplantation and support the theory that islet transplantation may represent the most physiologic replacement of hormonal deficiencies in the diabetic recipient.

Animals↗